Introduction To Botany Nabors Ebook Readers
Eden Alvardo
The transportation structure exists between the two right-of-way boundaries. Its primary purpose is to provide a safe, smooth, solid surfaced area to move vehicles on efficiently. All other concerns are secondary or less. Thus the main purpose of the non-surfaced areas i.e., fore slope, ditch, back slope and other vegetated areas - is to provide stability to and protection for the surfaced areas from damage or traffic interruption. The ecological approach is a naturally stabilizing approach for vegetation whereas the agronomic approach is a disturbing approach (mowing, broadcast spraying with the negative effects of the accompanying power equipment).
Coincidentally a National Cooperative Highway Research Program 14-16 project with the Transportation Research Board overlapped this work in 2009. We thank Ian Heap, lead investigator on that team, for sharing the specific weed controls for 40 species of common invasive plants, often found on noxious weed lists. Another research project is reflected in the section on GPS use in inventory work. Thanks to Victor Maddox of Mississippi State University for the applied research and the training manual we hope all States will utilize.
Our respect and appreciation go to Kirk Henderson of the National Center for Roadside Vegetation in Cedar Falls, Iowa, for his input into Part 3: Native Plant Establishment. The Iowa experience with native plantings, expanding production of native ecotype seed and natural selection, along with the legislated Iowa Living Roadside Trust accomplishments, should be a model to all States.
Highway corridors connect us all via our commercial transport, recreational excursions, workday travel, and more. The mobility and safety of U.S. highways is a proud accomplishment of the Federal Highway Administration with its State and local partners. Highway rights-of-way are the most visible of all public lands and likely the least understood. This manual is especially written for those decision-makers in maintenance, landscape, environmental services, and turf and erosion control to share what we know about managing this land.
Why did this 1930s understanding of roadsides and the natural environment not continue? This question has no easy answer. It likely involves a combination of factors: the economy, war, building of the interstate system, increased regulations, and a view of roadsides as extra real estate for further expansion of infrastructure. Whatever the reasons, more roads meant more development and more disturbance of the environment. Application of ecological principles to roadsides was not a priority.
In the 1970s, during the energy crunch, some DOTs and land management agencies in need of economic solutions moved away from the traditional agricultural approach. The needs of public lands were not the same as those of a farm field. Using the local natural plant life found as part of the context of the project once again made sense. It was during this era that some embraced reduced mowing of roadsides to reduce the use of costly fuels. Using the inexpensive tool of fire to manage native remnants and native plants reduced costs as well. Preserving remnant native vegetation was preferred, because it was cheaper and required less energy than seeding newly disturbed soils. Pragmatism shifted practices on the ground. This shift to an ecological approach resulted in less surface water runoff, increased native seed source, more diversity and improved aesthetics.
Forty years later, while still trying to do the right thing, we are once again stressed by an economic crisis, higher fuel costs, and climate change considerations. It is time for all land managers to reconsider an ecological approach.
Humans alter landscapes for our own uses. Historically environmental and ecological impacts were not considered when land use projects were planned. We have learned that these actions have definite significant impacts, and that it is more cost effective to plan to minimize impacts and ensure that ecological integrity is retained than to abandon an area and find a new alternative or restore a severely impacted area.
Using an ecological approach to land management is valuable because, plain and simple, it works and saves resources in the long run. In order to properly manage a roadside habitat and minimize damage so that the ecosystem will continue to function properly, it is critical to understand what makes up the ecosystem (plant and animal species, soils, water, weather, etc.), how the ecosystem works, what the limiting factors are, and how much impact it will withstand while still retaining its integrity as a functioning ecosystem.
The five principles are time, species, place, disturbance, and landscape. For greater detail on the five principles and especially on the guidelines (which we will only list here) please refer to the original source at Ecological Principles and Guidelines for Managing the Use of Land by V. H. Dale, S. Brown, R. A. Haeuber, N. T. Hobbs, N. Huntly, R. J. Naiman, W. E. Riebsame, M. G. Turner and T. J. Valone. Ecological Applications Vol. 10, No. 3 (Jun., 2000), pp. 639-670. Published by: Ecological Society of America.
TIME Ecosystems function at many time scales, from the very long (geologic weathering of rock to form soil) to the very short (metabolic processes within a plant or animal). Ecosystems can change over time, and left alone, the natural pattern of plant succession will take a disturbed roadside Right-Of-Way (ROW) to a relatively stable plant community which will vary depending on regional conditions.
SPECIES It is important to understand the species of plants and animals present in the ecosystem because these species often have complex interdependencies. A butterfly relies on a plant species to survive. Remove the plant and the butterfly will be gone too. What species are native to the area and what introduced alien species are threatening the area? Retain and/or restore the native species if at all possible.
PLACE This principle stresses the importance of understanding the unique characteristics of the specific habitat. What are the plant and animal organisms present, the soil types, water regime, prevailing climate, and geomorphology (slope, orientation, etc.) that characterize the habitat? Any land management project must consider these specific characteristics because the species that will be established (or maintained) in the habitat must be able to survive within these constraints.
DISTURBANCE Disturbance of a habitat is the result of natural events, such as wildfires or floods, or human activities, including clearing native vegetation for agriculture or logging, building transportation systems, or controlling rivers via damming or levees. The type of disturbance will affect the plant and animal populations that become established after the disturbance.
LANDSCAPE The size, shape, and spatial relationships of the land-cover types (forest edge, grassland, etc.) present will control the types of plants and animals that can exist in the habitat. Generally larger habitats support a wider range of species and are more stable than smaller habitats with fewer species. However, small, patchy habitats also can be valuable.
The Land Use Initiative of the ESA used the five ecological principles described above to develop eight land use guidelines to assist managers in planning roadside vegetation projects. Following these guidelines can help ensure that projects will maintain the integrity of the impacted habitat while still serving the intended human needs. We will only list the guide lines here and suggest the reader refer to the original source for the specifics of the guidelines.
Ecoregions provide a way for land managers to manage and monitor ecosystems more efficiently. Just as the physical and biological resources within an ecoregion can be described with some degree of confidence, the responses of that ecoregion to disturbances can be predicted. This aspect of predictability allows for more efficient management!
The landscape is more complex than just forests, grasslands, and wetlands. Within any ecosystem, province, or natural region are local assemblages of species known as plant communities. Collectively, these plant communities are called vegetation. Vegetation differs in kinds of species and total number of species depending on the local soil and moisture conditions. Although plant communities differ from region to region, they have great similarities in composition and structure. A mesic prairie in Wisconsin does not differ greatly from a mesic grassland in Kansas, and a lowland forest in West Virginia is very similar to a lowland forest in Missouri. Understanding plant communities allows us to share solutions to road-side issues across the country. No State, with the exception of Hawaii, has discreet plant communities.
The NRCS uses this system, described in the Agriculture Handbook 296 (USDA 2006), to assist in making national and regional land use decisions, identifying research and inventory needs, and extrapolating research results across political boundaries. MLRA maps data for the entire United States, the Caribbean, and the Pacific Basin, are available on the USDA web site at
Areas within a Division have similar overall climates but are subdivided by precipitation and temperature. Divisions are further subdivided into Provinces, which are similar in vegetation cover types.
After the most general ecosystem classification (Level I) was published in 1987, various States, EPA Regions and Research Labs decided they needed greater detail for their management and research purposes. Cooperative efforts began to develop higher level maps. The Level III map was revised in December 2011 and is available at -research/level-iii-and-iv-ecoregions-epa-region. Level IV maps are being developed and are available at -research/level-iii-and-iv-ecoregions-epa-region.
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